Personally, if I'm in a coffee shop or any store with some people, I pull out my wallet and subtly show them my Xapo debit card. Then they get curious on what kind of card is that since it doesnt look like the usual Mastercard or creditcard. Then I explain it from there on.
What's your way of spreading Bitcoin knowledge?

I also did it some time ago where I showed two of my classmates my bitcoin wallet then the amount inside it as well as its price in my local currency and as usual they get curious too and asked how is it considered as a money or how it can used to buy some stuffs and how can I convert it into cash . I explained to them how can bitcoin works and how it can be used as a medium of exchange or payment, why it has a value and lastly how am I earning it .
I actually did exactly what you are doing mates but I did it with my friends. At first they are confused but suddenly they got interested. I hard a hard time explaining them because I was just a neophyte and has limited ideas that time but still managed to give them knowledge on Bitcoins and introduce them this helpful forum. As time have passed I can see their interest fading but then came a time when I made a cashout for about two hundred fifty dollars worth of our local currency last October first just this month. I showed them my money and they ask me like "Oh! How did you get that amount of money?" and I replied "I got this from signature campaigns so if I were you keep on posting constructively and on topic so if you reach junior member you could participate and get accepted easily." I think three of my friends are now member ranks. I told them also to spread the good news too so they can also help others with financial problems like me. I just warned them to obey the forum rules for better results. And hopefully they will soon learn and earn too just like almost anyone with higher ranks.